1. Field of the Invention
This invention relates generally to irrigation systems, and more particularly to sprinkler head guards.
2. Description of the Prior Art
An irrigation or sprinkling system typically includes a matrix of buried water pipes, a number of vertically oriented pipe (known as risers) attached to the buried water pipes, and a sprinkler head attached to the top of each riser.
While there are many types of sprinkler heads, a common type includes a base, a spray nozzle, and a poppet attaching the spray nozzle to the base. When water pressure is applied to the base of the sprinkler head through the riser, the poppet is caused to move from a retracted to an extended position, elevating the spray nozzle.
In a typical home installation, the sprinkler heads are mostly buried in the ground, with only their upper surface being at ground level. The poppet elevates the spray nozzle above the ground level for effective dispersal of the water. A problem encountered with this type of installation is that it can be easily damaged by being stepped upon, mowed over, etc.
To combat this problem, a number of individuals have developed protectors or guards for sprinkler heads. For example, U.S. Pat. No. 3,904,120 of Sbicca teaches a thick, plastic disk adapted to be recessed into a lawn around a sprinkler head. The disk is molded in one piece and is provided with a central aperture having a shoulder which contacts and supports a radial flange of the sprinkler head.
A problem with sprinkler head protectors of the prior art is that while they adequately protect the sprinkler head itself, they do not protect the riser connecting the sprinkler head to the buried water pipes. In consequence, the risers, which are usually made from fragile polyvinylchloride (PVC) plastic, are often broken and must be dug out and replaced.
For example, with the sprinkler head protector of Sbicca, any vertical load exerted on the protector will cause the shoulder within the cavity of the protector to exert a force on the sprinkler head's flange. The relatively strong sprinkler head (which is typically made from a metal such brass) will transmit this force to the easily breakable riser.